CVE-2023-52935
What it is
In the Linux kernel, the following vulnerability has been resolved: mm/khugepaged: fix ->anon_vma race If an ->anon_vma is attached to the VMA, collapse_and_free_pmd() requires it to be locked. Page table traversal is allowed under any one of the mmap lock, the anon_vma lock (if the VMA is associated with an anon_vma), and the mapping lock (if the VMA is associated with a mapping); and so to be able to remove page tables, we must hold all three of them. retract_page_tables() bails out if an ->anon_vma is attached, but does this check before holding the mmap lock (as the comment above the check explains). If we racily merged an existing ->anon_vma (shared with a child process) from a neighboring VMA, subsequent rmap traversals on pages belonging to the child will be able to see the page tables that we are concurrently removing while assuming that nothing else can access them. Repeat the ->anon_vma check once we hold the mmap lock to ensure that there really is no concurrent page table access. Hitting this bug causes a lockdep warning in collapse_and_free_pmd(), in the line "lockdep_assert_held_write(&vma->anon_vma->root->rwsem)". It can also lead to use-after-free access.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Analyzed
Affected
- Debian Linux 11.0
- Linux Kernel < 5.4.299
- Linux Kernel < 5.10.243
- Linux Kernel < 5.15.192
- Linux Kernel < 6.1.11
- Linux Kernel 6.2
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2023-52935.md and follow it. Check whether this project is affected by CVE-2023-52935. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/023f47a8250c6bdb4aebe744db4bf7f73414028b
- https://git.kernel.org/stable/c/352fbf61ce776fef18dca6a68680a6cd943dac95
- https://git.kernel.org/stable/c/abdf3c33918185c3e8ffeb09ed3e334b3d7df47c
- https://git.kernel.org/stable/c/acb08187b5a83cdb9ac4112fae9e18cf983b0128
- https://git.kernel.org/stable/c/cee956ab1efbd858b4ca61c8b474af5aa24b29a6
References
- https://git.kernel.org/stable/c/023f47a8250c6bdb4aebe744db4bf7f73414028b
- https://git.kernel.org/stable/c/352fbf61ce776fef18dca6a68680a6cd943dac95
- https://git.kernel.org/stable/c/abdf3c33918185c3e8ffeb09ed3e334b3d7df47c
- https://git.kernel.org/stable/c/acb08187b5a83cdb9ac4112fae9e18cf983b0128
- https://git.kernel.org/stable/c/cee956ab1efbd858b4ca61c8b474af5aa24b29a6
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html